As is appreciated by those skilled in the art of building construction, a head-of-wall joint (also sometimes referred to as a top-of-wall joint) refers to the junction or interface existing between a building wall and the ceiling (where the ceiling may also be a floor or corrugated pan roof deck, for example). Head-of-wall joints often present a serious challenge in terms of reducing or preventing the spread of smoke and fire during a building fire. In this regard and in common practice, a wall to ceiling connection of many newly constructed buildings consists essentially of an inverted U-shaped (or M-shaped) elongated steel channel (or track) configured to receive steel studs between the legs of the shaped channel. A wallboard is generally attached to at least one side of the studs. The studs and wallboard are in many instances spaced apart from the ceiling a short gap distance in order to allow for ceiling deflections caused by seismic activity or moving overhead loads. Channel and stud assemblies that allow for ceiling deflections are commonly referred to as dynamic head-of-wall systems. Exemplary steel stud wall constructions may be found in U.S. Pat. Nos. 4,854,096 and 4,805,364 both to Smolik, and U.S. Pat. No. 5,127,203 to Paquette. Exemplary dynamic head-of-wall systems having steel stud wall constructions may be found in U.S. Pat. No. 5,127,760 to Brady, and U.S. Pat. No. 6,748,705 to Orszulak et al.
In order to contain the spread of smoke and fire, a fire resistant material such as, for example, mineral wool is often times stuffed into the gaps between the ceiling and wallboard. For example, mineral wool is often stuffed between a steel header beam (e.g., an elongated U-shaped channel) and a corrugated or fluted steel roof deck (used in many types of steel and concrete building constructions); a fire resistant and generally elastomeric spray coating is then applied onto the exposed mineral wool to thereby form a fire resistant joint seal. In certain situations where the ceiling to wallboard gap is relatively small, a fire resistant and elastomeric caulk is commonly applied so as to fill any small gaps. In still another approach and as disclosed in U.S. Pat. Nos. 5,471,805 and 5,755,066 both to Becker, a slidable noncombustible secondary wall member is fastened to an especially configured steel header beam and immediately adjacent to the wallboard. In this configuration, the secondary wall member provides a fire barrier that is able to accommodate ceiling deflections. All of these approaches, however, are relatively labor intensive and thus expensive.
Intumescent materials have been used to seal certain types of construction gaps such as, for example, conduit through-holes. In this regard, intumescent and fire barrier materials (often referred to as firestop materials or fire retardant materials) have been used to reduce or eliminate the passage of smoke and fire through openings between walls and floors and the openings caused by through-penetrations (i.e., an opening in a floor or wall which passes all the way through from one room to another) in buildings, such as the voids left by burning or melting cable insulation resulting from a fire in a modern office building. Characteristics of fire barrier materials suitable for typical commercial fire protection use include flexibility prior to exposure to heat, the ability to insulate and/or expand, and the ability to harden in place upon exposure to fire (i.e., to char sufficiently to deter the passage of heat, smoke, flames, and/or gases). Although many such materials are available, the industry has long sought better and more effective uses of these materials and novel approaches for better fire protection, especially in the context of head-of-wall construction joints and gaps.
Thus, and although construction joints and gaps are generally sealed in some manner (e.g., mineral wool and/or elastomeric coatings), there are few products and methods available for effectively and efficiently sealing head-of-wall construction joints and gaps (to thereby significantly enhance the ability of such joints and gaps to withstand smoke and fire penetration). In particular, there are very few products and methods available that address the needs for adequate fire protection sealing of dynamic head-of-wall systems associated with steel stud wall constructions. Thus, there is still a need in the art for new and improved fireblocks and fire retarding devices, including related wall assemblies, systems and methods. The present invention fulfills these needs and provides for further related advantages.